Answer:
In a tunnel of darkness lies a beast or iron. It can only attack when pulled back. What is it?
A large oasis in the desert. Come with cash and leave with none.
Turns me on my backs and open up my stomach. You will be the wisest of men though at start a lummox.
I fill a room but take no space.
I have a ring but no fingers. I used to stay still all the time but nowadays I follow you around.
What never gets any wetter no matter how hard it rains?